GB2320091A - Combined dustcap and air pressure gauge - Google Patents

Abstract

A tyre pressure gauge has a screwable exterior casing (1, fig.1) securely attachable to a valve 2 and an interior with several cylinders 3, 9, 11 twistable and depressable so as to simultaneously cause the release of air from the valve and to extend telescopically thereby registering and gauging, by readings on the body of the cylinders, the pressure exerted by the released air and returnable to their original position.

Description

COMBINED DUSTCAP AND AIR PRESSURE GAUGE This invention relates to a motor vehicle tyre gauge integral to a tyre or inner tube valve and acting also as a dust cap.

The use of tyre gauges to measure and test pressure in tyres on road vehicles is a well established principle in the practice of ensuring such tyres are properly inflated and so avoiding undue wear, liability of punctures and general safety. However, the process by which this is normally achieved, either by entering a garage and using their equipment or buying and utilising a personal pressure tester requires effort and time, and despite the essential importance of such checks may be neglected unless the tyres in question are obviously low in pressure or impossible due to the absence of a convenient tyre pressure gauge.

According to the present invention, there is provided a combined dustcap and tyre pressure gauge permanently and securely attachable to a valve comprising an outer casing and one or more inner cylinders with release mechanisms and movable parts operable to release air from the valve forcing the cylinders to extend upwards telescopically to register released air pressure.

The said gauge being so designed as to provide a hollow cylindrical outer casing open top and bottom and provided with an inner screw thread at the bottom end compatible with the screw thread on the outer end of the tyre valve provided for a dust cap and so permitting this bottom end of the gauge casing to be accurately attachable to a given valve and screwable into place thus securing the outer casing of the invention to the vehicle valve screw thread exterior. Such outer casing also having an angled slot in it's side and on the top outer lip a series of castelated evenly spaced flanges.

In addition, the design provides that within the said outer casing of the gauge is contained a first inner cylinder open at the top and base possessing a small flange situated on the upper inner rim and having a diameter such as to permit free vertical movement within the outer casing with such free vertical movement being governed and guided by a lever fixedly attached to the exterior body of the inner cylinder and positioned so as to protrude outwards through the angled slot in the outer casing of the gauge.

Such protruding lever accommodated by the angled slot in the outer casing being so designed as to be easily accessed for external manipulation to create a downwards pressure, such pressure being transformed into a lateral angled motion by the angle of the slot in the body of the outer casing such that the attached body of the inner cylinder is thus moved simultaneously sideways and downwards.

In addition the said first inner cylinder has within the diameter of it's open base a cross member or similar arrangement containing a pin or other protruberance being vertically aligned and fixed so that when the gauge outer casing is screwably attached on the outer body of the tyre valve the said pin is exactly positioned above the air release button within the tyre valve at a precise distance such that when the first inner cylinder is pressed laterally downwards via the protruding lever, the pin may travel downwards and contact touch upon and depress open the internal tyre valve button thus releasing pressurised air upwards through and into the body of the inner cylinder.

According to the present invention, inside the aforementioned inner cylinder is contained a second inner cylinder open top and bottom with a small exterior flange situated on it's lower outer rim such that as the second inner cylinder rises within the body of the first inner cylinder, the said flanges on both bodies may be brought into contact acting as a stop and thus preventing the two cylinders separating. Such flanges being so designed as to slide evenly and closely against the body of the adjacent cylinder creating a air tight seal. Both cylinders having vertical guides of a complimentary tongue and groove design or similar arrangement such that movement in the vertical plane of one cylinder body occurs in strict alignment with the other at all times.

In addition, the said second inner cylinder possesses a further small flange situated in it's top inner r nm and has situated within it's length a third inner cylinder, such cylinder having a closed top and open base and possessing a small flange on it's bottom outer lip such flange acting as a stop against the upper inner rim flange on the second inner cylinder thus acting to prevent separation of the two cylinders when the third inner cylinder is extended outwards to it's full length.

Such third inner cylinder also possessing guides with vertical tongue and grooving ensuring movement in the vertical plane is continually and firmly aligned at all times with the first and second inner cylinders and such flanges as detailed being so designed to ensure an air tight fit against the body of an adjacent cylinder.

In addition, the stipulated third inner cylinder being so designed in length that when all three inner cylinders are contained and aligned within the external casing of the gauge the upper end of the third inner cylinder protrudes proud of the first and second inner cylinders and casing having on it's upper outer lip a series of spaced flexible castelated flanges that align overlap and grip the castellated flanges situated at the top outer lip of the outer casing such arrangement holding the third inner cylinder firmly in place within the body of the second inner cylinder and casing.

The proportion and spacing of the castillated flanges on the outer upper rim of the third inner cylinder and the degree to which they overlap those of the exterior casing being such that when the first inner cylinder is depressed downwards and laterally via the lever protruding from the external casing, such motion turns simultaneously the fixedly aligned second and third inner cylinders and the said castellated flanges. Such flanges thus freed of the restraining exterior flanges on the outer upper rim of the exterior casing allowing the third inner cylinder to freely rise upwards within the inner body of the second inner cylinder. Such movement upwards in turn raising the second inner cylinder by way of the contact between the complimentary rim fixures on their respective upper inner and lower outer lip and guiding the two cylinders.

Energy for such upwards movement of the second and third inner cylinders being provided by a simultaneous release of compressed air caused by the sustained lateral depression of the first inner cylinder and resultant pressure by the pin or protruberance at it's base upon the air release button inside the tyre valve.

In addition the present invention provides for the arrangement of several coiled springs operating so as to govern and control the movement of the several inner cylinders. Such that the first inner cylinder is provided with a coiled spring situated below it's base and locked against the upper rim of the tyre valve screw thread when the exterior case is screwably fixed so as to be permanently held in a state of semi-compression and fully compressed only when the first inner cylinder is depressed via the external lever.

Such spring thus providing an upwards pressure to return the first inner cylinder and it's fixed lever to their original position vertically and laterally when released.

In addition, a second coiled spring situated between the lower outer flange of the second inner cylinder and the upper inner flange of the first inner cylinder being designed to provide a calibrated degree of resistance to the upper motion of the second inner cylinder when following the third inner cylinder upwards under pressure of air released from the tyre valve. Such resistance offering calculated value to the pressure exerted by such released air and thus tyre pressure where such calculation is primarily expressed by the vertical movement of the third inner cylinder marked externally on a scale such that the scale is clearly visible when the inner cylinder protrudes upwards from the outer casing under pressure of released air from the valve and tyre.

Such scale being duly calibrated so as to offer accurate resistance to air pressure released from within a given tyre expressed in psi or other recognised standards or a code designed for easy reading such as a simplified colour code or similar. An additional spring between the inner upper rim of the second inner cylinder and the lower outer rim of the third inner cylinder performs an identical function.

In addition the present invention acts when securably in place as a dustcap and so prevent the ingress of dirt and other substances which would cause the valve to work poorly or not at all.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which Figure 1 Shows the assembled gauge with outer sleeve and inner cylinder flanges overlapping the flanges on the outer casing and position of external slot.

Figure 2 Shows the assembled gauge in cross section with the outer sleeve cut away, revealing the body banel and castelated flanges of the outer casing.

Figure 3 Shows the same cross section/cut away as in Figure 2, but with the first inner cylinder barrel cut away to reveal the second and third inner cylinders.

Figure 4 Shows a semi-cross section/cut away with the exterior lever and attached first inner cylinder together with the two aligned second and third inner cylinders depressed and the tyre valve opened.

Also the new position of the castellated flanges on the inner cylinder.

Figure 5 Shows a semi-cross section/cut away showing the second and third inner cylinders released and raised by air released from the open valve into full extended position.

Referring to the drawing the integral tyre gauge comprises an outer casing 1 (Figure 1 ) screwably securable to the valve housing 2 (Figure 1, 2 ) and having a set of castelated flanges on it's upper outer lip 5 (Figure 2, 3 ) and an angled slot in it's body 16 (Figure 1). Within the outer casing is a first cylinder with an open grid base with pin protruberance 8 (Figure 2) and a body lever 4 (Figure 1) positioned so as to protrude from the angled slot in the casing 1 (Figure 1).

Two further inner cylinders 11/9 (Figure 3 ) are contained within the first cylinder and locked in vertical alignment by guides 17 (Figure 2, 5 ) The innermost cylinder 9 (Figure 3, 5 ) having a set of flexible castelated flanges on the exterior upper side.

In order to activate the gauge the lever 4 (Figure 1 ) is pressed down and across in the direction of arrow 12 (Figure 4 ) within the guide slot 16 (Figure 1 ) in the outer casing 1 and so forcing the first cylinder 3 and downwards and pressing the pin 8 at it's semi-open base onto the tyre valve 6 and releasing pressurised air. Due to the vertical alignment guides 17 the two further inner cylinders 11/9 also travel down and across in line with the first inner cylinder 3.

The depressing/twisting motion of the first inner cylinder 3 turns the castelated flanges 10 (Figure l ,2 2, 4) on the innermost cylinder sideways freeing them from the castelated flanges 5 on the outer casing. This allows the innermost cylinder having a closed top 18 (Figure 1 ) to rise under the air released from the open valve 6 (Figure 4 ) in direction of arrow 15 (Figure 5 ) and reaching full height raise in turn the second inner cylinder 11 (Figure 3, 5) via the lip 13 (Figure 5 ).

Readings on the body of the inner cylinders can then be taken indicating the air pressure. The lever 4 is then released, returning to it's original position via the pressure from the internal spring 7 (Figure 3 ) returning the flexible flanges 10 on the innermost cylinder 9 into vertical alignment with the flanges 5 on the outer casing 1.

This allows the gauge to be closed down by simply pressing on the closed top of the inner cylinder 9 until the both sets of flanges 5/10 are in contact and overlap securing the gauge in the ready for use position.

Claims (6)

1. A combined dustcap and tyre pressure gauge permanently and securely attachable to a valve comprising an outer casing and one or more inner cylinders with release mechanisms and movable parts operable to release air from the valve forcing the cylinders to extend upwards telescopically to register released air pressure.

2. A tyre pressure gauge as claimed in Claim 1 wherein the outer casing contains flanges that align with flexible flanges on an inner cylinder such that one secures and is movable laterally to release the other.

3. A tyre pressure gauge as claimed in Claim 1 and Claim 2 wherein an open bottomed inner cylinder features a cross member and protrusion so that when depressed will open the tyre valve.

4. A tyre pressure gauge as claimed in Claim 1 and Claim 2 and Claim 3 wherein guides are aligned along the sides of the inner cylinders providing precise vertical alignment at all times.

5. A tyre pressure gauge as Claim l and Claim 2 and Claim 3 and Claim 4 wherein the inner cylinders contain a number of springs so configured as to ensure the inner telescopic cylinders are pressured so as to retain a tension when idle and to act as a restraint on the telescopic motion of the vertical movement providing the basis for a measurable degree of pressure from the air when released from the valve.

6. A combined dust cap and tyre guage substantially as described herein with referance to Figures 1-5 of the accompanying drawing.